1. Field of the Invention
This invention lies in the field of fluid flow devices. More particularly, it concerns the field of ball valves.
Still nore particularly, it concerns the design of a flexible seal ring means for sealing between the housing of the valve, and the ball.
2. Description of the Prior Art
In the prior art, there are types of seal rings provided, incuding O-rings and the like, for sealing between the housing and the ball of a ball valve. Each of these have weaknesses of one sort or another, the most common weakness being an inability to provide an adjustable pressure to press the sealing lips against the sealing surface of the ball. The present invention is designed to overcome this weakness and includes a spring means which is incorporated as part of the seat ring, so that adequate spring pressure is provided to continuously maintain sufficient pressure of the sealing medium against the surface of the ball, so as to prevent leakage.